Get certain strings only (PHP) - php

Question

Text:
TestString
HT-Child1 CLASS-Class1
AnotherString
HT-Child2 CLASS-Class2
HT-Child3 CLASS-Class3
HT-Child4 CLASS-Class4
CLASSOFWEEK-Class
What I have so far: (Inside $display->getExtraHTML() is the text). Could someone guide me towards what I need to do to adapt my code to get the results I want.
<?php
$additionalHTML = explode("\n", $display->getExtraHTML());
$html = "";
$html .= "<ul>";
foreach($additionalHTML as $key => $item){
$html .= "<li>$item</li>";
}
$html .= "</ul>";
echo $html;
?>
I know I can use something like this to get string between, but how do I use it to get all the values i need?
$string = strstr($display->getExtraHTML(), "HT-"); // gets all text from HT
$string = strstr($string, "CLASS-", true); // gets all text before CLASS
Can I use both explode and strstr to get to where I want?
Expect HTML markup:
Expected Result: (Get the values from HT- and CLASS-)
<ul>
<li>Child1 Class1</li>
<li>Child2 Class2</li>
<li>Child3 Class3</li>
<li>Child4 Class4</li>
</ul>

Answer 1

Complete solution with preg_match_all function:
$txt = '
TestString
HT-Child1 CLASS-Class1
AnotherString
HT-Child2 CLASS-Class2
HT-Child3 CLASS-Class3
HT-Child4 CLASS-Class4
CLASSOFWEEK-Class';
preg_match_all('/^HT-(\S+)\s+CLASS-(\S+)/m', $txt, $m);
$html = "<ul>";
if (isset($m[1]) && isset($m[2])){
foreach(array_map(null, $m[1], $m[2]) as $pair){
$html .= "<li>". implode(' ', $pair) ."</li>";
}
}
$html .= "</ul>";
echo $html;
The output (push Run code snippet):
<ul><li>Child1 Class1</li><li>Child2 Class2</li><li>Child3 Class3</li><li>Child4 Class4</li></ul>

Answer 2

Here's the solution
<?php
$str = "TestString
HT-Child1 CLASS-Class1
AnotherString
HT-Child2 CLASS-Class2
HT-Child3 CLASS-Class3
HT-Child4 CLASS-Class4
CLASSOFWEEK-Class";
$additionalHTML = explode("\n", $str);
$html = "";
$html .= "<ul>";
foreach($additionalHTML as $key => $item){
if(substr($item,0,3) == "HT-") {
$i = explode(" ",$item);
$a = substr($i[0],3);
$b = substr($i[1],6);
$html .= "<li>$a"." ". "$b</li>";
}
}
$html .= "</ul>";
echo $html;
Result
Child1 Class1
Child2 Class2
Child3 Class3
Child4 Class4

Answer 3

You may use regex, to find the matching lines and extract required data:
if(preg_match("/HT-([A-Za-z0-9]+) CLASS-([A-Za-z0-9]+)/", $item, $output))
{
$html .= "<li>".implode(" ",array_slice($output,1))."</li>";
}